• Title/Summary/Keyword: Prevention of deterioration

Search Result 161, Processing Time 0.029 seconds

Climate Change Impact on Korean Stone Heritage: Research Trends and Prospect (국내 석조유산의 기후변화 영향: 연구동향과 미래전망)

  • Kim, Jiyoung
    • Journal of Conservation Science
    • /
    • v.32 no.3
    • /
    • pp.437-448
    • /
    • 2016
  • Studies on vulnerability of cultural heritage and adaptation strategy to worldwide climate change have been actively carried out in advanced countries since the late 20th century, and this established a valid research methodology and piled up climate and deterioration dataset in the field of climate change. Meanwhile, we still have tasks to acquire related scientific data despite referencing political researches in Korea. Applying Korean future climate to impact analysis, deterioration of Korean stone heritage is likely prospected to change into complexity in terms of physical, chemical and biological weathering that may bring impacts on conservation business and administrative field of cultural heritage. Further studies will ensure detailed implication of climate change impact on Korean stone heritage by means of down-scaling analysis of areas to local scale and dataset frequency to an hour. It is important to sort out capability and vulnerability of the stone heritage to future environment, and to make an adaption and prevention strategies.

Selection of Portland Cement for Prevention of Sulfate Attack-Part 1 Sodium Sulfate Attack (황산염침식 방지를 위한 포틀랜드시멘트의 선정-Part 1 황산나트륨 침식)

  • Kim, Jong-Pil
    • Journal of the Korea Concrete Institute
    • /
    • v.21 no.4
    • /
    • pp.441-447
    • /
    • 2009
  • This paper presents a detailed experimental study on the sulfate resistance of specimens made with portland cement exposed to sulfate attack. The mortar specimens were immersed in a 5% sodium sulfate solution for 360 days and regularly monitored for visual damage, compressive strength loss and expansion. In addition, at the end of 360 days, the products of sulfate attack and the mechanism of attack were investigated through X-ray diffraction, TG&DSC and scanning electron microscopy. The test results indicated that the sulfate deterioration data was ordinary portland cement > sulfate resistance portland cement > low heat portland cement. The microstructural studies indicated that the main reaction product of deterioration of the mortar specimens was the formation of ettringite, gypsum and thaumasite due to sulfate attack. For portland cement matrices, a low heat cement matrix containing the lowest C3A and silicate ratio (C/S) was beneficient against the sulfate attack.

Development of overhead distribution line diagnosis system program (가공 배전선로 진단시스템 프로그램 개발)

  • Dong Hyun Chung;Deok Jin Lee
    • Smart Media Journal
    • /
    • v.12 no.5
    • /
    • pp.81-87
    • /
    • 2023
  • In this paper, accidents in high-voltage overhead distribution lines, which provide stable power supply in the power system, cause inconvenience in life and disruption of production of companies. 22.9 [kV] high-voltage overhead power distribution lines aim to improve reliability and stability, such as damage caused by rain, snow, wind, etc., or electric shock prevention. Therefore, in order to prevent wire disconnection accidents due to deterioration of electrical conductivity or tensile strength due to corrosion of overhead distribution lines, it is necessary to prevent unexpected accidents in the future through regular inspection and repair. In order to diagnose deterioration due to corrosion of distribution lines, a diagnostic system (measuring instrument) is installed on the wires to monitor the condition of the wires. The manager on the ground receives the measured data through ZigBee wireless communication, controls the diagnosis system through the diagnosis system program, and grasps the condition of the overhead distribution line through the measured data and photographed photos, and predicts the life of the wire along with the visual inspection method. developed a program.

Petrological Characteristics and Nondestructive Deterioration Assessments for Foundation Stones of the Sebyeonggwan Hall in Tongyeong, Korea (통영 세병관 초석의 암석학적 특성 및 비파괴 손상평가)

  • Han, Doo Roo;Kim, Sung Han;Park, Seok Tae;Lee, Chan Hee
    • Economic and Environmental Geology
    • /
    • v.54 no.2
    • /
    • pp.199-212
    • /
    • 2021
  • The Sebyeonggwan Hall (National Treasure No. 305) is located on the Naval Headquarter of Three Provinces in Tongyeong, and it has partly undergone with several rebuilding, remodeling, repairing and restorations since it's the first establishment in Joseon Dynasty (AD 1605) of ancient Korea. This study focuses on 50 foundation stones that comprise the Sebyeonggwan. These stones are made of six rock types and currently have various shapes of the surface damages. As the foundation stones, the dominant rock type was dacitic lapilli tuffs, and provenance-based interpretation was performed to supply alternative stones for conservation. Most of the provenance rocks for foundation stones showed highly homogeneity with their corresponding stones of petrography, mineralogy and magnetic susceptibility. According to surface deterioration assessments, the most serious damages of the stones were blistering and scaling. The deterioration mechanism was identified through the analysis of inorganic contaminants, and the primary reason is considered salt weathering caused by sea breeze and other combined circumstances. Based on the mechanical durability of the stones, there was no foundation stone that required the replacement of its members attributed to the degradation of the rock properties, but conservation treatment is considered necessary to delay superficial damage. The foundation stones are characterized by a combined outcome of multiple petrological factors that caused physical damage to surfaces and internal defects. Therefore, it's required to diagnosis and monitoring the Sebyeonggwan regularly for long-term preservation.

Experimental Study on the Toxicity Characteristics of Non-Class 1E Cables according to Accelerated Deterioration (가속열화에 따른 비안전등급 케이블의 독성특성에 관한 실험적 연구)

  • Jang, Eun-Hui;Kim, Min-Ho;Lee, Min Chul;Lee, Sang-Kyu;Moon, Young-Seob
    • Fire Science and Engineering
    • /
    • v.33 no.6
    • /
    • pp.105-113
    • /
    • 2019
  • This study investigates the toxicity characteristics of two Non-Class 1E Cables (For security reasons, we refer to company A and company B) used in nuclear power plants according to the accelerated deterioration period. In accordance with NES 713 test equipment and standards, tests were carried out on non-aged cables and the cables subjected to 20- and 40-year-accelerated-deterioration; each of the cables was further classified into sheath and insulation. The test results showed that the toxicity indices of 20- and 40-year-accelerated-aged cables were higher than those for the non-aged cables, and 20-year-aged cables of both A and B companies showed the highest toxicity indices. This is attributed to the extensive emissions of carbon monoxide and halide gases such as hydrogen chloride and hydrogen bromide. Furthermore, to analyze the toxicity indices of sheath and insulation in detail, the US Department of Defense standard (MIL-DTL) was applied to determine whether the Toxicity index (T.I.) allowance was exceeded, and the results showed that the insulating materials emitted considerably more than the allowable limit.

Prognostic Value of Serum AFP, AFP-L3, and GP73 in Monitoring Short-term Treatment Response and Recurrence of Hepatocellular Carcinoma after Radiofrequency Ablation

  • Wang, Nan-Ya;Wang, Cong;Li, Wei;Wang, Guan-Jun;Cui, Guo-Zhen;He, Hua;Zhao, Heng-Jun
    • Asian Pacific Journal of Cancer Prevention
    • /
    • v.15 no.4
    • /
    • pp.1539-1544
    • /
    • 2014
  • Purpose: Alpha-fetoprotein (AFP), Lens culinaris agglutinin-reactive fraction of AFP (AFP-L3), and Golgi protein 73 (GP73) levels have been widely used as tumor markers for the diagnosis of hepatocellular carcinoma (HCC). The aim of this study was to investigate whether these tumor markers could be used to monitor short-term treatment response and recurrence of HCC in patients undergoing radiofrequency ablation (RFA). Methods: Between July 2012 and July 2013, 53 consecutive patients with newly diagnosed HCC were prospectively enrolled in this study. Among these, 32 patients underwent RFA, after which they were followed up prospectively at the First Hospital of Jilin University in China. Results: AFP, AFP-L3, and GP-73 values pre-RFA were not associated with tumor size, whereas AFP and GP-73 levels tended to be associated with tumor number, the presence of vascular invasion, deterioration of liver function, advanced-stage disease, and a poor performance status. GP-73 levels were dramatically elevated in the patients with hepatitis C-associated HCC. Neither pre-RFA nor 1-month post-RFA tumor marker values were associated with short-term outcome. The short-term recurrence rate of AFP-positive patients measured 1 month post-RFA was obviously higher than that of AFP-negative patients. Conclusions: AFP and GP-73 values were associated with clinical variables representing tumor growth and invasiveness, and the AFP value measured 1 month post-RFA was a strong predictor of short-term recurrence in patients with HCC.

Overexpression and Clinicopathological Contribution of DcR3 in Bladder Urothelial Carcinoma Tissues

  • Jiang, Yi-Qiang;Zhong, Teng-Fei;Dang, Yi-Wu;Zou, Ling-Song;Yang, Liu;Yang, Xia;Chen, Gang
    • Asian Pacific Journal of Cancer Prevention
    • /
    • v.15 no.21
    • /
    • pp.9137-9142
    • /
    • 2014
  • Background: To explore the expression of DcR3 protein and its clinicopathological significance in bladder urothelial carcinomas (BUC). Materials and Methods: Immunohistochemistry was performed to detect the expression of DcR3, caspase-3, Bcl-2, VEGF, Ki-67, PCNA and P53 in 166 BUC and 56 normal bladder tissues. Western blotting was used to detect the expression of DcR3 in the supernatants of cultured BUC cells. Results: Overexpression of DcR3 was found in BUC tissues and cell lines, with significant elevation as compared to normal bladder tissues (p<0.0001). Higher DcR3 expression was related to the status of invasion, lymph node metastasis and recurrence. Furthermore, DcR3 expression was negatively correlated with caspase-3 and positively associated with Bcl-2, VEGF, Ki-67 labeling index (LI), PCNA LI and P53 (all p<0.0001), respectively. Conclusions: DcR3 may play a crucial role as an oncogene in tumorigenesis, deterioration and progress of BUC via influencing related pathways of apoptosis, proliferation and angiogenesis. The detection of DcR3 protein in the formalinfixed and paraffin-embedded samples could assist to predict in prognosis of BUC patients.

Prisoners' Perception of Tobacco Use and Cessation in Chhatisgarh, India - The Truth from Behind the Bars

  • Tiwari, Ram Vinod;Megalamanegowdru, Jayachandra;Parakh, Abhinav;Gupta, Anjali;Gowdruviswanathan, Shailarani;Nagarajshetty, Praveen Malavalli
    • Asian Pacific Journal of Cancer Prevention
    • /
    • v.15 no.1
    • /
    • pp.413-417
    • /
    • 2014
  • Background: Prisoners represent a population group that is disadvantaged, socially deprived and underprivileged, needing particular attention with regard to provision of necessary oral health care, health promotion and motivation and tobacco cessation. Considering the situation in prisons, smoking and tobacco chewing are burning issues related to health deterioration and economic loss that seem to be overlooked by the public health sectors. Aim: To assess prisoners' perception of tobacco use and cessation in Chhatisgarh, India. Materials and Methods: A pre-tested, close ended questionnaire was administered in the form of extensive face to face interviews, to assess perceptions regarding tobacco use and cessation in the central jail of Durg District of Chhattisgarh state, India. Results: Prevalence of tobacco usage amongst the prisoners was found to be 61%. Some 27% reported smoking, 44% used tobacco in the chewable form and 29% indulged in consuming tobacco in both forms i.e. smoked as well as chewed. Results suggest several recommendations for policy relevance such as provision of a prison dentist, a tobacco cessation counseling program and targeted eradication of oral cancer by educating the prisoners. Conclusions: Health is a fundamental human "right of everyone to the enjoyment of the highest attainable standard of physical and mental well-being". This applies to prisoners just as it does to every other human being. The alarming findings in the study suggest the need for dental treatment facilities and tobacco cessation counseling in prisons.

Prospects for Building a Legal System for Marine Environment Protection in China (중국의 해양환경법제 분석과 전개방향에 관한 고찰)

  • Yang, Hee-Cheol;Park, Seong-Wook;Park, Su-Jin;Kwon, Suk-Jae
    • Ocean and Polar Research
    • /
    • v.30 no.1
    • /
    • pp.89-107
    • /
    • 2008
  • Marine environment is subject serious destruction because of frequent accidents during exploration of marine resources and overseas transport. Also, as many industrial enterprises discharge high volume of wastes and contamination, marine pollution has become a serious threat to people (especially in China). China is quickly becoming a world economic leader of the 21st century. Rapid industrialization and social changes have raised the standard of living of millions of the Chinese, mainly in the areas of East and South East coast. The process of industrialization, however, is often followed by deterioration of the marine environment and rarely turned around until a country has increased its standard of living. Solving these array of problems will take decades and currently the government is addressing minor specific issues only. Fortunately, the Chinese government has enacted a number of marine pollution control laws. On 25 December 1999, the 13th Session of the Ninth Standing Commettee of the National People's Congress passed the amended the Marine Environment Protection Law of the People's Republic of China. This Law establishes rights and responsibilities of the relevant departments concerning marine environment management and provides for two new chapters on "Marine Environment Supervision" and "Marine Ecological Protection", along with "Supervision of Pollution Prevention for Marine Construction Projects", "Marine Ecological Protection" and "Marine Environment Pollution Prevention for Marine Construction Projects". Also, the Law was amended with provisions for integrated pollution discharge control system and oil spillage emergency response plan and enhanced legal responsibilities. Chinese government recognizes that international and national experience can be useful for China to prevent further ecological degradation of the marine environment.

Dairy Dietary Calcium and Osteoporosis - An Overview

  • Jayaprakasha, H.M.;Yoon, Y.C.
    • Journal of Dairy Science and Biotechnology
    • /
    • v.22 no.2
    • /
    • pp.143-150
    • /
    • 2004
  • The osteoporosis is a disease characterized by lower bone mineral content, deterioration of bone tissue and a reduction in the protein and mineral matrix of the bone. The bone becomes more porous leading to increased bone fragility and risk of fracture, particularly of the hip, spine and wrist. Osteoporosis can result in disfigurement, lowered self·esteem, reduction or loss of mobility, and decreased independence. Adequate calcium intake through milk and milk products in childhood and adolescence is a decisive marker for obtaining a maximum bone mass (peak adult bone mass) and f3r the prevention of osteoporosis. Calcium is one of the most critical nutrients associated with the osteoporosis. Dietary calcium is of great significance for healthy skeletal growth and development. The bone mineral content and bone mineral density of young adults is directly related to the calcium intake through milk and dairy products. Milk and milk products are the important sources of calcium as the richness and bioavailability of this nutrient is very high as compared to other food products. If enough calcium is not supplemented through diet, calcium from the bone will be depleted to maintain the blood plasma calcium level. The article focuses on the various issues related to osteoporosis manifestation and the role of dietary calcium especially calcium derived from dairy products.

  • PDF